# How non-ballistic are ski jumpers? **URL:** \ **Category:** Factual Questions\ **Created:** [February 15, 2022, 6:12pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548 "2022-02-15T18:12:54Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [February 15, 2022, 6:12pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/1 "2022-02-15T18:12:54Z")
It’s understood that long-distance ski jumpers can win or lose based on how they manage their aerodynamics after they leave the ramp. But how much difference does it actually make? If I launch a 150-pound steel missile from the ski jump at the same speed and trajectory as a departing skier, how much farther down the hill will the skier land? ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [February 15, 2022, 6:16pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/2 "2022-02-15T18:16:06Z")
never mind ---
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [February 15, 2022, 6:25pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/3 "2022-02-15T18:25:28Z")
According to [this](https://vault.si.com/vault/1988/01/27/riding-the-air) old SI article, quite a bit. > Although to the novice viewer it may appear that all ski jumpers simply cannonball down to the end of the ramp and land as far down the hill as their momentum will take them, in truth the ones who plane into the wind and use the air as a lifting medium go much farther. Felder sometimes sails more than 270 feet in the 70-meter event. (Typically a ski jumper gets no more than 15 feet off the ground during his flight.) But when Felder crashed, he had traveled less than half that distance, even though his speed had been approximately the same as in a good jump—50 mph. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [February 15, 2022, 6:43pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/4 "2022-02-15T18:43:35Z")
Those skis are massive - the surface area relative to the size/mass of the skier looks similar to the wings of an actual glider. Apparently the regulations restrict ski length to 145% of the skier’s height, with a reduction if you have unusually low BMI. And this rule was introduced because lightness was such a huge advantage that there were major issues with eating disorders and unhealthy weights in the sport. > **[Battle of Weight Versus Gain in Ski Jumping (Published 2010)](https://www.nytimes.com/2010/02/12/sports/olympics/12skijump.html)** > > Officials say the most severe cases of underweight jumpers have been halted, but current rules still encourage jumpers to remain thin. I can’t find any numbers yet, but @RitterSport’s datapoint suggesting doubling the ballistic distance would not be surprising. ---
**Author:** ![EinsteinsHund](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/einsteinshund/32/8400_2.png) [@EinsteinsHund](https://boards.straightdope.com/u/EinsteinsHund)\ **Post date:** [February 15, 2022, 7:35pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/5 "2022-02-15T19:35:44Z")
Don’t forget that the jumpers not merely run over the edge of the ski jump, but take a massive upwards jump, which must be timed exactly. If you miss the right moment, your jump is ruined. It’s a very, very complicated and complex sport, though it might look effortlessly when a world class jumper does it. The jumpers’ suits also have a big aerodynamic influence , that’s why they are rigidly regulated and carefully inspected. ---
**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\ **Post date:** [February 15, 2022, 7:51pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/6 "2022-02-15T19:51:06Z")
> [@EinsteinsHund](#): > > The jumpers’ suits also have a big aerodynamic influence , that’s why they are rigidly regulated and carefully inspected. Yes and five women were disqualified for clothing reasons last week. > **[5 women ski jumpers are disqualified at the Olympics over their jumpsuits](https://www.npr.org/2022/02/08/1079212805/ski-jumping-suit-violation-winter-olympics)** > > "The sport of ski jumping has experienced one of its darker days," a Norwegian official said, after athletes from some of the top medal-contending teams were disqualified from competing. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [February 15, 2022, 8:16pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/7 "2022-02-15T20:16:42Z")
> [@EinsteinsHund](#): > > Don’t forget that the jumpers not merely run over the edge of the ski jump, but take a massive upwards jump, which must be timed exactly. Yes. In my ballistic comparison (see my OP), it’s important that the ballistic projectile leave at the same departure angle as the skier - including the effects of the skier’s upward jump. > [@Riemann](#): > > I can’t find any numbers yet, but @RitterSport’s datapoint suggesting doubling the ballistic distance would not be surprising. Thinking about this further, the hill is probably making this difference seem more dramatic than it really is. Given that the skier is generally is no more than 15’ above the ground (see @RitterSport’s post above, #3) a small difference in the the angle of descent for the skier and the steel missile can account for a very large difference in how far downslope each of them lands. Turning this on its head, it’s starting to sound like there may be a rather modest aerodynamic influence imparted by the jumper - but that the geometry of the hill allows that modest aerodynamic influence to have a very large effect on the jump distance. It would be interesting to understand the actual trajectories and speeds of a jumper and steel missile between the ramp and the landing zone. From that (and the hill geometry), it would be possible to estimate the actual aerodynamic forces (direction and magnitude) being developed by the jumper throughout their flight. ---
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [February 15, 2022, 9:21pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/8 "2022-02-15T21:21:01Z")
> [@Machine\_Elf](#): > > It would be interesting to understand the actual trajectories and speeds of a jumper and steel missile between the ramp and the landing zone. I found that article by searching for “ski jumping cannonball”, hoping someone would have done the exact analysis you’re looking for, but I couldn’t find it. It’s possible that the aerodynamics of the way the ski jumper “flies” help to overcome the effect of the wind resistance of a body- and ski-shaped object. That is, maybe a heavy arrow on tiny skis would fly almost as far, but a person not trying to fly would go a far shorter distance. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [February 15, 2022, 9:29pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/9 "2022-02-15T21:29:36Z")
> **[The Freaky Physics of Ski Jump](https://www.smithsonianmag.com/science-nature/the-freaky-physics-of-ski-jump-180979554/)** > > Olympic ski jumpers do everything they can do counteract the effects of gravity and fly as far as they can down hills ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [February 15, 2022, 10:14pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/10 "2022-02-15T22:14:09Z")
Don’t we have Eddie “the Eagle” Edwards for a base comparison? ---
**Author:** ![Horatius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/horatius/32/3572_2.png) [@Horatius](https://boards.straightdope.com/u/Horatius)\ **Post date:** [February 15, 2022, 10:24pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/11 "2022-02-15T22:24:46Z")
Now I want to see a new form of biathlon: ski jumping and hang gliding. Or maybe wingsuits. ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [February 15, 2022, 10:28pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/12 "2022-02-15T22:28:49Z")
Ski jumping while shooting skeet? Not a close-range spectator sport! I’d watch that for sure. ---
**Author:** ![Horatius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/horatius/32/3572_2.png) [@Horatius](https://boards.straightdope.com/u/Horatius)\ **Post date:** [February 15, 2022, 10:31pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/13 "2022-02-15T22:31:01Z")
> [@Tride](#): > > Ski jumping while shooting skeet? All the other competitors line up along the slope, and try to hit the person in the air. Last person without an injury wins. ---
**Author:** ![Tride](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tride/32/13907_2.png) [@Tride](https://boards.straightdope.com/u/Tride)\ **Post date:** [February 15, 2022, 10:33pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/14 "2022-02-15T22:33:43Z")
With paintball guns? Would definitely spice it up. Wear a cup, boys! ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 15, 2022, 10:56pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/15 "2022-02-15T22:56:02Z")
Surely, a ski jumper’s velocity at the end of the ramp is something routinely measured and known? It’d be easy to calculate the ballistic distance from that. ---
**Author:** ![EinsteinsHund](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/einsteinshund/32/8400_2.png) [@EinsteinsHund](https://boards.straightdope.com/u/EinsteinsHund)\ **Post date:** [February 15, 2022, 10:59pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/16 "2022-02-15T22:59:46Z")
Of course it is, it’s usually displayed the moment the jumper takes off on TV (of course it depends on the respective ski jump, but it’s usually in the ballpark of 90-100 kph) . It’s one of the crucial parameters (of many) for the jump. ---
**Author:** ![Horatius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/horatius/32/3572_2.png) [@Horatius](https://boards.straightdope.com/u/Horatius)\ **Post date:** [February 15, 2022, 11:19pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/17 "2022-02-15T23:19:52Z")
> [@Tride](#): > > With paintball guns? Would definitely spice it up. Wear a cup, boys! Skeet Jumping is a sport that requires commitment, you poser. Like [Olympic Being Eaten by a Crocodile](https://www.youtube.com/watch?v=8T7KWV73N3s). ---
**Author:** ![3AxisCtrl](https://avatars.discourse-cdn.com/v4/letter/3/ecd19e/32.png) [@3AxisCtrl](https://boards.straightdope.com/u/3AxisCtrl)\ **Post date:** [February 15, 2022, 11:19pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/18 "2022-02-15T23:19:56Z")
> [@Chronos](#): > > It’d be easy to calculate the ballistic distance from that. In addition to velocity, you’d need: - Wind - Air density - Drag coefficient - Precise shape of the hill’s landing area ---
**Author:** ![3AxisCtrl](https://avatars.discourse-cdn.com/v4/letter/3/ecd19e/32.png) [@3AxisCtrl](https://boards.straightdope.com/u/3AxisCtrl)\ **Post date:** [February 15, 2022, 11:30pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/19 "2022-02-15T23:30:40Z")
Here’s an old video of [rolling tires down a ski jump](https://www.youtube.com/watch?v=OJKraZb4FPQ). It’s of little use here: no skier’s jump distances are presented, and of a rolling tire’s total energy, a fair fraction is rotational. It does seem as if the tires fall well short of what a human might do. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 15, 2022, 11:38pm UTC](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548/20 "2022-02-15T23:38:21Z")
The wind, air density, and drag coefficient are precisely what you don’t need to calculate the ballistic distance. Though you would need the shape of the landing area, but I would expect that that’s also well-known. [Next page](https://boards.straightdope.com/t/how-non-ballistic-are-ski-jumpers/959548.md?page=2)